What size outboard would be appropriate for a 14' aluminum starcraft with with a floor and a couple seats? It came with a 20hp which has never run well. It is rated up to 35hp. Ive been looking for outboards as a backup plan if i cannot fix mine. I see alot of 15hp available. Would this be too small to plane out ? I am new to this and dont want to make another mistake. thanks for advice in advance.